Exploring the complementarity of pancreatic ductal adenocarcinoma preclinical models

Purpose: Compare pancreatic ductal adenocarcinoma (PDAC), preclinical models, by their transcriptome and drug response landscapes to evaluate their complementarity. Experimental De-sign: Three paired PDAC preclinical models—patient‐derived xenografts (PDX), xenograft‐derived pancreatic organoids (XDPO) and xenograft‐derived primary cell cultures (XDPCC)—were derived from 20 patients and analyzed at the transcriptomic and chemosensitivity level. Transcriptomic characterization was performed using the basal‐like/classical subtyping and the PDAC molecular gradient (PAMG). Chemosensitivity for gemcitabine, irinotecan, 5‐fluorouracil and oxaliplatin was established and the associated biological pathways were determined using independent component analysis (ICA) on the transcriptome of each model. The selection criteria used to identify the different components was the chemosensitivity score (CSS) found for each drug in each model. Results: PDX was the most dispersed model whereas XDPO and XDPCC were mainly classical and basal-like, respectively. Chemosensitivity scoring determines that PDX and XDPO display a positive correlation for three out of four drugs tested, whereas PDX and XDPCC did not correlate. No match was observed for each tumor chemosensitivity in the different models. Finally, pathway analysis shows a significant association between PDX and XDPO for the chemosensitivity‐associated pathways and PDX and XDPCC for the chemoresistance‐associated pathways. Conclusions: Each PDAC preclinical model possesses a unique basal‐like/classical transcriptomic phenotype that strongly in-fluences their global chemosensitivity. Each preclinical model is imperfect but complementary, sug-gesting that a more representative approach of the clinical reality could be obtained by combining them. Translational Relevance: The identification of molecular signatures that underpin drug sensitivity to chemotherapy in PDAC remains clinically challenging. Importantly, the vast majority of studies using preclinical in vivo and in vitro models fail when transferred to patients in a clinical setting despite initially promising results. This study presents for the first time a comparison between three preclinical models directly derived from the same patients. We show that their applica-bility to preclinical studies should be considered with a complementary focus, avoiding tumor-based direct extrapolations, which might generate misleading conclusions and consequently the overlook of clinically relevant features.Fil: Hoare, Owen. Centre National de la Recherche Scientifique; FranciaFil: Fraunhoffer Navarro, Nicolas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Elkaoutari, Abdessamad. Centre National de la Recherche Scientifique; FranciaFil: Gayet, Odile. Centre National de la Recherche Scientifique; FranciaFil: Bigonnet, Martin. Centre National de la Recherche Scientifique; FranciaFil: Roques, Julie. Centre National de la Recherche Scientifique; FranciaFil: Nicolle, Rémy. No especifíca;Fil: McGuckin, Colin. Cell Therapy Research Institute; FranciaFil: Forraz, Nico. Cell Therapy Research Institute; FranciaFil: Sohier, Emilie. Le Centre Régional de Lutte Contre Le Cancer Léon Bérard; FranciaFil: Tonon, Laurie. Le Centre Régional de Lutte Contre Le Cancer Léon Bérard; FranciaFil: Wajda, Pauline. Le Centre Régional de Lutte Contre Le Cancer Léon Bérard; FranciaFil: Boyault, Sandrine. Le Centre Régional de Lutte Contre Le Cancer Léon Bérard; FranciaFil: Attignon, Valéry. Le Centre Régional de Lutte Contre Le Cancer Léon Bérard; FranciaFil: Tabone, Luciana Belen. Le Centre Régional de Lutte Contre Le Cancer Léon Bérard; FranciaFil: Barbier, Sandrine. No especifíca;Fil: Mignard, Caroline. No especifíca;Fil: Duchamp, Olivier. No especifíca;Fil: Iovanna, Juan. Centre National de la Recherche Scientifique; FranciaFil: Dusetti, Nelson J.. Centre National de la Recherche Scientifique; Franci

EZH2 alterations in follicular lymphoma: biological and clinical correlations

International audienceThe histone methyltransferase EZH2 has an essential role in the development of follicular lymphoma (FL). Recurrent gain-of-function mutations in EZH2 have been described in 25% of FL patients and induce aberrant methylation of histone H3 lysine 27 (H3K27). We evaluated the role of EZH2 genomic gains in FL biology. Using RNA sequencing, Sanger sequencing and SNP-arrays, the mutation status, copy-number and gene-expression profiles of EZH2 were assessed in a cohort of 159 FL patients from the PRIMA trial. Immunohistochemical (IHC) EZH2 expression (n = 55) and H3K27 methylation (n = 63) profiles were also evaluated. In total, 37% of patients (59/159) harbored an alteration in the EZH2 gene (mutation n = 46, gain n = 23). Both types of alterations were associated with highly similar transcriptional changes, with increased proliferation programs. An H3K27me3/me2 IHC score fully distinguished mutated from wild-type samples, showing its applicability as surrogate for EZH2 mutation analysis. However, this score did not predict the presence of gains at the EZH2 locus. The presence of an EZH2 genetic alteration was an independent factor associated with a longer progression-free survival (hazard ratio 0.58, 95% confidence interval 0.36–0.93, P = 0.025). We propose that the copy-number status of EZH2 should also be considered when evaluating patient stratification and selecting patients for EZH2 inhibitor-targeted therapies

Alterations in Homologous Recombination-Related Genes and Distinct Platinum Response in Metastatic Triple-Negative Breast Cancers: A Subgroup Analysis of the ProfiLER-01 Trial

International audienc

An injectable and porous hydrogel with potential as a support for functional skeletal muscle regeneration

International audienc

Versatile injectable and porous hydrogels: new perspectives for skeletal muscle tissue regeneration

International audienc

Versatile injectable and porous hydrogels: new perspectives for skeletal muscle tissue regeneration

International audienc

Versatile injectable and porous hydrogels: new perspectives for skeletal muscle tissue regeneration

International audienc

Design of injectable and porous hydrogels and their potential as support for skeletal muscle tissue engineering

International audienc

Immunological and classical subtypes of oral premalignant lesions

International audienceOral squamous cell carcinoma (OSCC) is a major cause of cancer-associated morbidity and mortality and may develop from oral premalignant lesions (OPL). An improved molecular classification of OPL may help refining prevention strategies. We identified two main OPL gene-expression subtypes, named immunological and classical, in 86 OPL (discovery dataset). A gene expression-based score was then developed to classify OPL samples from three independent datasets, including 17 (GSE30784),13 (GSE10174) and 15 (GSE85195) OPLs, into either one of the two gene-expression subtypes. Using the single sample gene set enrichment analysis, enrichment scores for immune-related pathways were different between the two OPL subtypes. In OPL from the discovery set, loss of heterozygosities (LOH) at 3p14, 17p13, TP53, 9p21 and 8p22 and miRNA gene expression profiles were analyzed. Deconvolution of the immune infiltrate was performed using the Microenvironment Cell Populations-counter tool. A multivariate analysis revealed that decreased miRNA-142-5p expression (P = 0.0484) and lower T-cell, monocytic and myeloid dendritic cells (MDC) immune infiltration (T-cells, P = 0.0196; CD8 T cells, P = 0.0129; MDC, P = 0.0481; and monocytes, P = 0.0212) were associated with oral cancer development in the immunological subtype only. In contrast, LOH at 3p14 (P = 0.0241), 17p13 (P = 0.0348) and TP53 (P = 0.004) were associated with oral cancer development in the classical subtype only. In conclusion, we identified 2 subtypes of OPLs, namely immune and classical, which may benefit from different and specific personalized prevention interventions. ARTICLE HISTOR

Molecular profile to guide personalized medicine in adult patients with primary brain tumors: results from the ProfiLER trial

International audienceImmunohistochemistry and recent molecular technologies progressively guided access to personalized anti-tumoral therapies. We explored the feasibility, efficacy, and the impact of molecular profiling in patients with advanced brain tumors. This multicentric prospective trial ProfiLER enrolled patients with primary brain tumors, who have been pre-treated with at least one line of anti-cancer treatment, and for whom molecular profiles had been achieved using next-generation sequencing and/or comparative genomic hybridization on fresh or archived samples from tumor, relapse, or biopsies. A molecular tumor board weekly analyzed results and proposed molecular-based recommended therapy (MBRT). From February 2013 to December 2015, we enrolled 141 patients with primary brain tumor and analyzed 105 patients for whom tumor genomic profiles had been achieved. Histology mainly identified glioblastoma (N = 46, 44%), low-grade glioma (N = 26, 25%), highgrade glioma (N = 12, 11%), and atypical and anaplastic meningioma (N = 8, 8%). Forty-three (41%) patients presented at least one actionable molecular alteration. Out of 61 alterations identified, the most frequent alterations occurred in CDKN2A (N = 18), EGFR (N = 12), PDGFRa (N = 8), PTEN (N = 8), CDK4 (N = 7), KIT (N = 6), PIK3CA (N = 5), and MDM2 (N = 3). Sixteen (15%) patients could not be proposed for a MBRT due to early death (N = 5), lack of available clinical trials (N = 9), or inappropriate results (N = 2). Only six (6%) of the 27 (26%) patients for whom a MBRT had been proposed finally initiated MBRT (everolimus (N = 3), erlotinib (N = 1), ruxolitinib (N = 1), and sorafenib (N = 1)), but discontinued treatment for toxicity (N = 4) or clinical progression (N = 2). High-throughput sequencing in patients with brain tumors may be routinely performed, especially when macroscopic surgery samples are available; nevertheless delays should be reduced. Criteria for clinical trial enrollment should be reconsidered in patients with brain tumors, and a panel of genes specifically dedicated to neurologic tumors should be developed to help decision-making in clinical practice